Monitoring Proxy Information on Novell BorderManager
Novell Cool Solutions: Feature
By Manisha Malla
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Posted: 2 Aug 2002
Version: Novell BorderManager 3.7
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Novell BorderManager (NBM) Proxy Services can help improve performance by locally caching frequently requested Internet information. Proxy Services store copies of frequently requested Web information closer to the user, thereby reducing the number of times the same information is accessed over an Internet connection, the download time, and the load on the remote server.
Proxy Services issue Access Controls to applications to forward and filter connections for such services as HTTP and FTP. The host running Proxy Services is known as the gateway. In general, Proxy Services allow services only for which there are proxies. For example, if a gateway has proxies for FTP, then only FTP can be requested; requests for all other services are ignored.
With gateways, you can hide the names and addresses of internal systems--the gateway is the only hostname known outside the system. Also, traffic can be logged before it reaches the internal hosts. Proxy Services improves security by hiding private network domain names and addresses and sending all requests through a single gateway.
The NBM Proxy Console provides a number of screens to monitor the status of the Proxy and other related services. This AppNote attempts to explain some of the major screens and the information contained in them. It also discusses typical usage scenarios for some of the important fields.
- Proxy Cache Activity
The NBM Proxy Cache Activity screens help to monitor and diagnose the Proxy Cache status. The first two screens under Proxy Cache Activity provide the following statistics: Current Cache, Proxy Connection, and Data Transfer (both from Proxy Cache to browsers and from origin servers to Proxy Cache). The last two screens provide the Lists of Origin Hosts sorted in order of data transmitted either from cache to browsers or from origin server to cache. Hence, these screens help in monitoring the current Proxy Cache health, as well as the transfer of data to browsers either directly from cache or from origin servers via the cache.
- HTTP Proxy Statistics
The HTTP Proxy Statistics screens help you monitor the NBM HTTP Proxy activity. The two screens described below show the statistics for the HTTP Server and the HTTP Client. The HTTP Server listens for browser requests and sends replies to the browsers. The HTTP Client, on the other hand, sends requests to the origin servers. The Proxy Cache provides the communication between the two components.
When a request for a Web object arrives from a browser, the HTTP Server asks the Proxy Cache for the object. If the object is present in the cache, the HTTP Server is called which sends the cached object back to the browser. If the requested object is not present in the cache (or is stale), the cache invokes the HTTP Client which forms and sends a request to the origin server. These screens also show a brief summary of the Proxy Cache (for both HTTP and FTP Proxies).
- FTP Proxy Statistics
The FTP Proxy Statistics screen helps you monitor both Forward FTP Proxy and Reverse FTP Proxy (FTP Accelerator) statistics. The Forward FTP Proxy helps in controlling access to FTP sites. It can also be used to cache FTP data for anonymous users, thus enabling faster downloads. The Reverse FTP Proxy helps in accelerating FTP transfers from the Internet or intranet to the local FTP server. You can use the statistics screen described in this section to monitor the behavior of Forward and Reverse FTP Proxy.
- Transparent Proxy
The HTTP Transparent Proxy enables you to use an NBM server as the HTTP Proxy Server without having to specifically configure each user's browser to point to the Proxy Server. This feature can be used if each browser need not be reconfigured to point to the Proxy Server. It also helps in enforcing network security by ensuring that all HTTP requests pass through the Proxy. The screen described in this section helps you monitor Transparent Proxy activity.
- ICP Statistics
The screen described in this section helps you monitor Internet Cache Protocol (ICP) activity. The screen is updated only if the Proxy Server is configured as a Cache Hierarchy Client in NWAdmin. This is valid for all fields except "Total Cache Fill Requests" and "Fill From Origin." These two fields get updated even if ICP is not configured.
- DNS Statistics
The Domain Name System (DNS) screens help you monitor the DNS Lookup activity of the NBM Proxy. The three screens described in this section give a summary of the DNS Lookup statistics, the detailed information about a host as is stored in the DNS cache, and a listing of hostnames sorted in decreasing order of DNS lookups performed.
- Proxy Memory Usage and Connection Statistics
The Proxy memory usage and connection statistics screens help you track the system resources that NBM is allocated. The two screens described in this section show a breakdown of the memory and connections used by the various components of the Proxy. In scenarios where there is a high usage of system resources by the NBM Proxy, this can help you determine which component of the Proxy is causing the high usage.
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